org.fxmisc.undo.impl.MultiChangeUndoManagerImpl Maven / Gradle / Ivy
package org.fxmisc.undo.impl;
import org.reactfx.EventStream;
import java.time.Duration;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.function.BiFunction;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Predicate;
/**
* {@link UndoManagerImpl} specified for a {@link List} of changes
*
* @param the type of change to store in the list of changes to undo/redo
*/
public class MultiChangeUndoManagerImpl extends UndoManagerImpl> {
public MultiChangeUndoManagerImpl(
ChangeQueue> queue,
Function changeInvert,
Consumer> apply,
BiFunction> changeMerge,
Predicate changeIsIdentity,
EventStream> changeSource) {
this(queue, changeInvert, apply, changeMerge, changeIsIdentity, changeSource, Duration.ZERO);
}
public MultiChangeUndoManagerImpl(
ChangeQueue> queue,
Function changeInvert,
Consumer> apply,
BiFunction> changeMerge,
Predicate changeIsIdentity,
EventStream> changeSource,
Duration preventMergeDelay) {
super(
queue,
list -> {
List l = new ArrayList<>(list.size());
// invert the contents of the list
// and store them in reversed order
for (int i = list.size() - 1; i >= 0; i--) {
l.add(changeInvert.apply(list.get(i)));
}
return l;
},
apply,
(list1, list2) -> {
// if one list is empty, return the other list
if (list1.size() == 0) {
return Optional.of(list2);
} else if (list2.size() == 0) {
return Optional.of(list1);
}
// if both are the same size and every corresponding element
// can be merged, return a list with all merged items.
// Otherwise, return Optional.empty()
if (list1.size() == list2.size()) {
List mergeList = new ArrayList<>(list1.size());
for (int i = 0; i < list1.size(); i++) {
C item1 = list1.get(i);
C item2 = list2.get(i);
Optional merge = changeMerge.apply(item1, item2);
if (merge.isPresent()) {
mergeList.add(merge.get());
} else {
return Optional.empty();
}
}
return Optional.of(mergeList);
} else {
return Optional.empty();
}
},
list -> list.stream().allMatch(changeIsIdentity),
changeSource,
preventMergeDelay
);
}
}